Light sensitive compositions are widely used for various uses, for example for photoresist, plate materials for lithography or letterpress, presensitized plates (PS plate) for offset printing, information recording materials, materials for making a relief image, and the like.
There are problems that although many of these light sensitive compositions are light sensitive to ultraviolet rays, the photographic sensitivity thereof is generally several ten to several hundred mJ/cm.sup.2 and thus light sources of high output are required and moreover the efficiency of energy conversion to the recording is poor. On the other hand, there is an image-forming method wherein an image is directly formed using a light of high energy density such as laser. This method has not only an advantage that energy conversion efficiency becomes better but an advantage that image-forming steps may greatly be simplified. As for light sources for scanning exposure in direct image formation, it is advantageous to use visible light laser, which gives emission of radiation stable in lifetime and intensity, rather than ultraviolet laser. Thus, there has been desired the emergence of visible light sensitive composition having a sensitivity such that scanning exposure by visible light laser is possible, and many visible light sensitive compositons having a high sensitivity to Ar.sup.+ laser, which has a stable emission of radiation in a visible region of wavelength 488 nm, have been proposed (please refer, for example, to Japanese Laid-Open Patent Publications Nos. 31848/1987, 233736/1986 and 221403/1985, European Patent 55486, Printed Circuit World Convention IV, technical paper .circle.22 -2 in page 91 of Gists of the 1st Academic Lecture Mass Meeting of the Printed Circuit Society, etc.).
The form of these visible light sensitive compositions is liquid or film-like, but these compositions have the following drawbacks:
Liquid visible light sensitive compositions have many problems on workability, for example, that it is difficult to form a uniform and smooth film, it is difficult to apply them so as to make a desired film thickness, they cannot be applied uniformly onto a complicatedly-shaped article. Further, liquid visible light sensitive compositions also have the problem on safety and hygiene that they are harmful for human bodies because of high content of organic solvents therein.
On the other hand, visible light sensitive coats molded into a film-shape have the problems, for example, that an image formed by light application is not distinct because of thick film thickness of several ten micrometers, it is difficult to uniformly closely contact the film with the surface of a conductor, and products become expensive because the film cannot effectively be utilized due to unavoidable loss of the film.
Therefore, there has strongly been desired the appearance of visible light sensitive compositions to solve the above problems.